At https://phys.org/print419498625.html … two researchers from Aberystwyth University in Wales have used data from NASAs Solar Dynamics Observatory to look at the quiet sides of the solar corona. Most research has centred on the more active central band of the solar sphere where sun spots are more likely to occur. One thing the researchers wee looking at was extreme ultraviolet irradiance (EUV) and they expected big differences betwen the quiet side and the active hot spots. It seems the quiet latitudes dominate emissions of EUV whereas in the more active central region EUV emissions displayed variability. However, they also found the emission measurements from both the quiet and active regions was 'remarkably constant' – which must tell us something about the nature of the Sun. They also say that simply monitoring sun spots is an inadequate means for predicting EUV irradiance.